Oil is provided within an internal combustion engine to lubricate the movement of components of the engine. Additionally, the oil may be provided to cool components of the engine, such as pistons, when the engine is operating at high heat outputs.
The viscosity of the oil varies depending on its temperature. When the oil is cold, the viscosity of the oil may be high and the power required to pump oil around the engine may also be high. Additionally, when the oil is cold and viscous, the oil may not lubricate the components of the engine assembly as effectively and friction between the components may be increased. Furthermore, due to the viscosity of the oil, the movement of the components may generate increased shear forces within the oil, which may act against the movement of the components. It may therefore be desirable for the oil to be maintained at a temperature at which the oil has a suitable viscosity.
Before the engine is started, the engine and the oil are often cold. During warmup of the engine, components of the engine may be heated due to the operation of the engine more than other components, for example, a piston of the engine may be heated and may reach an operating temperature faster than a housing of the engine, such as a cylinder block. Coming into contact with the hot engine components may increase the temperature of the oil. However, the housing of the engine may act as a heat sink. When the oil contacts the housing, heat may be transferred into the housing, which may slow the warm-up of the oil, increasing the length of time required for the oil to reach a desired temperature and viscosity.